其實本來不想自己寫這樣一個類的，但找來找去都沒有找到符合生活習慣的，于是在經過反復的推敲設計后，嗚，我終于承認自己功力不夠---無法將內存管理與迭代器完美地結合在一起，只好只好先用std::vector了，于是便有了下面的代碼。到目前為止還不能號稱功能完善，但，但應該基本可用了，堪堪記在這里，也許能給以后的自己一些幫助，或可得到高手指點一二：
類文件被保存為datastream.hpp
#pragma once
/********************************************************************
created: 2008-10-13
author: lixianmin
purpose: used for data serialization and deserialization
Copyright (C) 2008 - All Rights Reserved
*********************************************************************/
#include <vector>
#include <cassert>
class datastream:public std::vector<char>
{
public:
datastream& operator<<(bool data){return push(data);}
datastream& operator<<(char data){return push(data);}
datastream& operator<<(wchar_t data){return push(data);}
datastream& operator<<(short data){return push(data);}
datastream& operator<<(int data){return push(data);}
datastream& operator<<(long data){return push(data);}
datastream& operator<<(float data){return push(data);}
datastream& operator<<(double data){return push(data);}
datastream& operator<<(unsigned char data){return push(data);}
datastream& operator<<(unsigned short data){return push(data);}
datastream& operator<<(unsigned int data){return push(data);}
datastream& operator<<(unsigned long data){return push(data);}
datastream& operator>>(bool& data){return pop(data);}
datastream& operator>>(char& data){return pop(data);}
datastream& operator>>(wchar_t& data){return pop(data);}
datastream& operator>>(short& data){return pop(data);}
datastream& operator>>(int& data){return pop(data);}
datastream& operator>>(long& data){return pop(data);}
datastream& operator>>(float& data){return pop(data);}
datastream& operator>>(double& data){return pop(data);}
datastream& operator>>(unsigned char& data){return pop(data);}
datastream& operator>>(unsigned short& data){return pop(data);}
datastream& operator>>(unsigned int& data){return pop(data);}
datastream& operator>>(unsigned long& data){return pop(data);}
datastream& test(bool& data){memcpy(&data, &operator[](0), sizeof(data));return *this;}
datastream& test(char& data){memcpy(&data, &operator[](0), sizeof(data));return *this;}
datastream& test(short& data){memcpy(&data, &operator[](0), sizeof(data));return *this;}
datastream& test(int& data){memcpy(&data, &operator[](0), sizeof(data));return *this;}
datastream& test(long& data){memcpy(&data, &operator[](0), sizeof(data));return *this;}
datastream& test(float& data){memcpy(&data, &operator[](0), sizeof(data));return *this;}
datastream& test(double& data){memcpy(&data, &operator[](0), sizeof(data));return *this;}
datastream& test(unsigned char& data){memcpy(&data, &operator[](0), sizeof(data));return *this;}
datastream& test(unsigned short& data){memcpy(&data, &operator[](0), sizeof(data));return *this;}
datastream& test(unsigned int& data){memcpy(&data, &operator[](0), sizeof(data));return *this;}
datastream& test(unsigned long& data){memcpy(&data, &operator[](0), sizeof(data));return *this;}
//std::string處理
datastream& operator<<(const char* data){return push(strlen(data), (void*)data);}
datastream& operator<<(const wchar_t* data){return push(wcslen(data)<<1, (void*)data);}
datastream& operator<<(const std::string& data){return push(data.size(), (void*)data.c_str());}
datastream& operator<<(const std::wstring& data){return push(data.size()<<1, (void*)data.c_str());}
datastream& operator>>(std::string& data)
{
size_t nSize;
pop(nSize);
std::vector<char>::iterator first=begin(), last=first+nSize;
data.assign(first, last);
erase(first, last);
return *this;
}
datastream& operator>>(std::wstring& data)
{
size_t nSize;
pop(nSize);
wchar_t* a=(wchar_t*)&operator[](0), *b=a+(nSize>>1);
data.assign(a, b);
std::vector<char>::iterator first=begin();
erase(first, first+nSize);
return *this;
}
datastream& test(std::string& data)
{
size_t nSize;
test(nSize);
std::vector<char>::iterator first=begin()+sizeof(nSize);
data.assign(first, first+nSize);
return *this;
}
datastream& test(std::wstring& data)
{
size_t nSize;
test(nSize);
wchar_t* first=(wchar_t*)&operator[](sizeof(nSize));
data.assign(first, first+(nSize>>1));
return *this;
}
//std::vector處理
template<typename C>
datastream& operator<<(const std::vector<C>& data)
{
size_t nSize=data.size();
push(nSize);
for (int i=0; i<nSize; ++i)
{
operator<<(data[i]);
}
return *this;
}
template<typename C>
datastream& operator>>(std::vector<C>& data)
{
size_t nSize;
pop(nSize);
C tmp;
for (int i=0; i<nSize; ++i)
{
operator>>(tmp);
data.push_back(tmp);
}
return *this;
}
private:
char* inc_size(size_t delta_size)
{
size_t last_size=size();
resize(last_size+delta_size);
return &operator[](last_size);
}
template<typename C>
datastream& push(C data)
{
memcpy(inc_size(sizeof(data)), &data, sizeof(data));
return *this;
}
datastream& push(size_t size, void* data)
{
push(size);
memcpy(inc_size(size), data, size);
return *this;
}
template<typename C>
datastream& pop(C& data)
{
memcpy(&data, &operator[](0), sizeof(data));
erase(begin(), begin()+sizeof(data));
return *this;
}
};
測試代碼：
#include <iostream>
#include <fstream>
#include <iterator>
#include "datastream.hpp"
template<typename T>
void print_vector(const std::vector<T>& v)
{
std::cout<<"---------------------------Print Vector---------------------------"<<std::endl;
std::copy(v.begin(), v.end(), std::ostream_iterator<T>(std::cout, "\n"));
std::cout<<"-------------------------Print Vector End-------------------------"<<std::endl;
}
int main(int argc, char* argv[])
{
std::string strPath="c:\\abc.txt";
std::vector<std::string> v;
v.push_back("hello world");
v.push_back("向量測試");
datastream ds;
ds<<318<<3.14159<<"hello world"<<std::string("中文測試")<<v;
std::ofstream outfile(strPath.c_str());
if (outfile)
{
std::copy(ds.begin(), ds.end(), std::ostreambuf_iterator<char>(outfile));
outfile.close();
std::cout<<"write to file successfully!"<<std::endl;
}
ds.clear(); //清空數據(但不釋放ds的內存)
std::ifstream infile(strPath.c_str());
if (infile)
{
ds.assign(std::istreambuf_iterator<char>(infile), std::istreambuf_iterator<char>()); //別忘了std::vector有個assign函數
int a;
double b;
std::string c, d;
std::vector<std::string> v2;
ds>>a>>b>>c>>d>>v2;
datastream(ds).swap(ds); //釋放datastream內存
std::cout<<"a="<<a<<", b="<<b<<", c="<<c<<", d="<<d<<std::endl;
print_vector(v2);
}
system("pause");
return 0;
}
輸出：
write to file successfully!
a=318, b=3.14159, c=hello world, d=中文測試
---------------------------Print Vector---------------------------
hello world
向量測試
-------------------------Print Vector End-------------------------
請按任意鍵繼續. . .